First Stage is a 5 micron particulate filter that removes water in liquid form, dirt, debris, rust and scale, a 9 oz bowl with sight glass and overnight drain. Second Stage is a .01 micron Oil Removing filter that removes oil aerosols and microscopic particles, a 9 oz bowl with sight glass and overnight drain. Third Stage is the 1-Gallon desiccant dryer that adsorbs water vapor producing a -30 degrees dew point, replace the desiccant beads when the beads turn from blue to pink. New design bowl for ease of desiccant bead replacement. Fourth Stage is a 3 micron Absolute filter to capture any desiccant dust protecting the precision regulator, a 9 oz bowl with sight glass and overnight drain. Fifth Stage precision regulator with gauge reduces pressure to required pressure. Replacement desiccant beads PneuMasterAir 3004 gallons.